unsigned char port_byte_in(unsigned short port) {
    unsigned char result;
    __asm__("in %%dx, %%al" :"=a"(result) :"d"(port));
    return result;
}

void port_byte_out(unsigned short port, unsigned char data) {
    __asm__("out %%al, %%dx" ::"d"(port), "a"(data));
}

unsigned char port_word_in(unsigned short port) {
    unsigned short result;
    __asm__("in %%dx, %%ax" :"=a"(result): "d"(port));
    return result;
}

void port_word_out(unsigned short port, unsigned short data) {
    __asm__("out %%ax, %%dx" ::"a"(data), "d"(port));
}